we have kept a lot of history books in our school library.(改为被动语态)

分类: 作业答案 • 2021-12-28 15:46:20

问题描述：

we have kept a lot of history books in our school library.(改为被动语态)
A lot of history books ____ ____ kept in our school library.

答

have been为啥？理由是……